Step 1

Preheat oven to 350°F. Line an 8-inch square pan with parchment paper and spray lightly with nonstick cooking spray.

Step 2

In a large bowl, stir together melted butter and brown sugar until smooth. Add egg and vanilla and stir until well combined.

Step 3

Measure out flour, baking powder and salt. Put into bowl right on top of wet ingredients, then stir until just combined.

Step 4

Spread batter into prepared pan. Bake for 25 to 28 minutes or until a toothpick inserted in the middle comes out with moist crumbs. The blondies will be slightly browned around the edges. Cool for at least 20 minutes in the pan before lifting the blondies out of the pan by grasping the edges of the parchment paper. Set on a wire rack to finish cooling.

Step 5

Cut into squares and store in an airtight container.